Adjustable extended electrode for edge uniformity control

ABSTRACT

Embodiments described herein generally related to a substrate processing apparatus. In one embodiment, a process kit for a substrate processing chamber disclosed herein. The process kit includes a ring having a first ring component and a second ring component, an adjustable tuning ring, and an actuating mechanism. The first ring component is interfaced with the second ring component such that the second ring component is movable relative to the first ring component forming a gap therebetween. The adjustable tuning ring is positioned beneath the ring and contacts a bottom surface of the second ring component. A top surface of the adjustable tuning ring contacts the second ring component. The actuating mechanism is interfaced with the bottom surface of the adjustable tuning ring. The actuating mechanism is configured to actuate the adjustable tuning ring such that the gap between the first ring component and the second ring component varies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/421,726, filed Feb. 1, 2017, which is herein incorporated byreference.

BACKGROUND Field

Embodiments described herein generally relate to a substrate processingapparatus, and more specifically to an improved process kit for asubstrate processing apparatus.

Description of the Related Art

As semiconductor technology nodes advanced with reduced size devicegeometries, substrate edge critical dimension uniformity requirementsbecome more stringent and affect die yields. Commercial plasma reactorsinclude multiple tunable knobs for controlling process uniformity acrossa substrate, such as, for example, temperature, gas flow, RF power, andthe like. Typically, in etch processes, silicon substrates are etchedwhile electrostatically clamped to an electrostatic chuck.

During processing, a substrate resting on a substrate support mayundergo a process that deposits material on the substrate and to remove,or etch, portions of the material from the substrate, often insuccession or in alternating processes. It is typically beneficial tohave uniform deposition and etching rates across the surface of thesubstrate. However, process non-uniformities often exist across thesurface of the substrate and may be significant at the perimeter or edgeof the substrate. These non-uniformities at the perimeter may beattributable to electric field termination affects and are sometimesreferred to as edge effects. During deposition or etching, a process kitcontaining at least a deposition ring is sometimes provided to favorablyinfluence uniformity at the substrate perimeter or edge.

Accordingly, there is a continual need for an improved process kit for asubstrate processing apparatus.

SUMMARY

Embodiments described herein generally related to a substrate processingapparatus. In one embodiment, a process kit for a substrate processingchamber disclosed herein. The process kit includes a ring, an adjustabletuning ring, and an actuating mechanism. The ring has a first ringcomponent and a second ring component. The first ring component isinterfaced with the second ring component such that the second ringcomponent is movable relative to the first ring component forming a gaptherebetween. The adjustable tuning ring is positioned beneath the ringand contacts a bottom surface of the second ring component. Theadjustable tuning ring has a top surface and a bottom surface. The topsurface of the adjustable tuning ring contacts the second ringcomponent. The actuating mechanism is interfaced with the bottom surfaceof the adjustable tuning ring. The actuating mechanism is configured toactuate the adjustable tuning ring such that the gap between the firstring component and the second ring component varies.

In another embodiment, a processing chamber is disclosed herein. Theprocessing chamber includes a substrate support member and a processkit. The substrate support member is configured to support a substrate.The process kit is supported by the substrate support member. Theprocess kit includes a ring, an adjustable tuning ring, and an actuatingmechanism. The ring has a first ring component and a second ringcomponent. The first ring component is interfaced with the second ringcomponent such that the second ring component is movable relative to thefirst ring component forming a gap therebetween. The adjustable tuningring is positioned beneath the ring and contacts a bottom surface of thesecond ring component. The adjustable tuning ring has a top surface anda bottom surface. The top surface of the adjustable tuning ring contactsthe second ring component. The actuating mechanism is interfaced withthe bottom surface of the adjustable tuning ring. The actuatingmechanism is configured to actuate the adjustable tuning ring such thatthe gap between the first ring component and the second ring componentvaries.

In another embodiment, a method of processing a substrate is disclosedherein. The substrate is positioned on a substrate support memberdisposed in a substrate processing chamber. A plasma is created above asubstrate. A height of a component of an edge ring is adjusted byactuating an adjustable tuning ring interfaced with the component tochange a direction of ions at an edge of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a cross sectional view of a processing chamber, according toone embodiment.

FIG. 2A is enlarged partial cross sectional view of the processingchamber of FIG. 1, according to one embodiment.

FIG. 2B is enlarged partial cross sectional view of the processingchamber of FIG. 1, according to one embodiment.

FIG. 3 is a simplified cross sectional view of a portion of theprocessing chamber of FIG. 1 depicting two capacitance paths, accordingto one embodiment.

FIG. 4A is a simplified cross sectional view of a portion of theprocessing chamber of FIG. 1, according to one embodiment, illustratinganother advantage of the present disclosure.

FIG. 4B is a simplified cross sectional view of a portion of theprocessing chamber of FIG. 1, according to one embodiment, illustratinganother advantage of the present disclosure.

For clarity, identical reference numerals have been used, whereapplicable, to designate identical elements that are common betweenfigures. Additionally, elements of one embodiment may be advantageouslyadapted for utilization in other embodiments described herein.

DETAILED DESCRIPTION

FIG. 1 is a cross sectional view of a processing chamber 100 having anadjustable tuning ring, such as an adjustable tuning ring 150illustrated in FIGS. 2A, 2B, 3, 4A, and/or 4B, according to oneembodiment. As shown, the processing chamber 100 is an etch chambersuitable for etching a substrate, such as substrate 101. Examples ofprocessing chambers that may be adapted to benefit from the disclosureare Sym3® Processing Chamber, C3® Processing Chamber, and Mesa™Processing Chamber, commercially available from Applied Materials, Inc.,located in Santa Clara, Calif. It is contemplated that other processingchamber, including deposition chambers and those from othermanufacturers, may be adapted to benefit from the disclosure.

The processing chamber 100 may be used for various plasma processes. Inone embodiment, the processing chamber 100 may be used to perform dryetching with one or more etching agents. For example, the processingchamber may be used for ignition of plasma from a precursor CxFy (wherex and y can be different allowed combinations), O2, NF3, or combinationsthereof.

The processing chamber 100 includes a chamber body 102, a lid assembly104, and a support assembly 106. The lid assembly 104 is positioned atan upper end of the chamber body 102. The support assembly 106 isdisclosed in an interior volume 108, defined by the chamber body 102.The chamber body 102 includes a slit valve opening 110 formed in asidewall thereof. The slit valve opening 110 is selectively opened andclosed to allow access to the interior volume 108 by a substratehandling robot (not shown).

The chamber body 102 may further include a liner 112 that surrounds thesupport assembly 106. The liner 112 is removable for servicing andcleaning. The liner 112 may be made of a metal such as aluminum, aceramic material, or any other process compatible material. In one ormore embodiments, the liner 112 includes one or more apertures 114 and apumping channel 116 formed therein that is in fluid communication with avacuum port 118. The apertures 114 provide a flow path for gases intothe pumping channel 116. The pumping channel 116 provides an egress forthe gases within the chamber 100 to vacuum port 118.

A vacuum system 120 is coupled to the vacuum port 118. The vacuum system120 may include a vacuum pump 122 and a throttle valve 124. The throttlevalve 124 regulates the flow of gases through the chamber 100. Thevacuum pump 122 is coupled to the vacuum port 118 disposed in theinterior volume 108.

The lid assembly 104 includes at least two stacked components configuredto form a plasma volume or cavity therebetween. In one or moreembodiments, the lid assembly 104 includes a first electrode 126 (“upperelectrode”) disposed vertically above a second electrode 128 (“lowerelectrode”). The upper electrode 126 and the lower electrode 128 confinea plasma cavity 130, therebetween. The first electrode 126 is coupled toa power source 132, such as an RF power supply. The second electrode 128is connected to ground, forming a capacitance between the two electrodes126, 128. The upper electrode 126 is in fluid communication with a gasinlet 134. The first end of the one or more gas inlets 134 opens intothe plasma cavity 130.

The lid assembly 104 may also include an isolator ring 136 thatelectrically isolates the first electrode 126 from the second electrode128. The isolator ring 136 may be made from aluminum oxide or any otherinsulative, processing compatible, material.

The lid assembly may also include a gas distribution plate 138 and ablocker plate 140. The second electrode 128, the gas distribution plate138, and the blocker plate 140 may be stacked and disposed on a lid rim142, which is coupled to the chamber body 102.

In one or more embodiments, the second electrode 128 may include aplurality of gas passages 144 formed beneath the plasma cavity 130 toallow gas from the plasma cavity 130 to flow therethrough. The gasdistribution plate 138 includes a plurality of apertures 146 configuredto distribute the flow of gases therethrough. The blocker plate 140 mayoptionally be disposed between the second electrode 128 and the gasdistribution plate 138. The blocker plate 140 includes a plurality ofapertures 148 to provide a plurality of gas passages from the secondelectrode 128 to the gas distribution plate 138.

The support assembly 106 may include a support member 180. The supportmember 180 is configured to support the substrate 101 for processing.The support member 180 may be coupled to a lift mechanism 182 through ashaft 184, which extends through a bottom surface of the chamber body102. The lift mechanism 182 may be flexibly sealed to the chamber body102 by a bellows 186 that prevents vacuum leakage from around the shaft184. The lift mechanism 182 allows the support member 180 to be movedvertically within the chamber body 102 between a lower transfer portionand a number of raised process positions. Additionally, one or more liftpins 188 may be disposed through the support member 180. The one or morelift pins 188 are configured to extend through the support member 180such that the substrate 101 may be raised off the surface of the supportmember 180. The one or more lift pins 188 may be activated by a liftring 190.

FIG. 2A is a partial cross sectional view of a portion of the processingchamber 100, illustrating a process kit 200 disposed therein on asupport member 180, according to one embodiment. The support member 180includes an electrostatic chuck 202, a cooling plate (or cathode) 204,and a base 206. The cooling plate 204 is disposed on the base 206. Thecooling plate 204 may include a plurality of cooling channels (notshown) for circulating coolant therethrough. The cooling plate 204 maybe engaged with the electrostatic chuck 202 by an adhesive or anysuitable mechanism. One or more power supplies 208 may be coupled to thecooling plate 204. The electrostatic chuck 202 may include one or moreheaters (not shown). The one or more heaters may be independentlycontrollable. The one or more heaters enable the electrostatic chuck 202to heat the substrate 101 from a bottom surface of the substrate 101 toa desired temperature.

The process kit 200 may be supported on the support member 180. Theprocess kit 200 includes an edge ring 210 having an annular body 212.The annular body 212 is split into two edge ring components 214, 216.The two edge ring components 214, 216 are interfaced with each othersuch that component 216 may be movable relative to component 214. Thefirst edge ring component 214 includes a top surface 218, a bottomsurface 220, an inner edge 222, and an outer edge 224. The top surface218 is substantially parallel to the bottom surface 220. The inner edge222 is substantially parallel to the outer edge 224, and substantiallyperpendicular to the bottom surface 220. In some embodiments, the firstedge ring component 214 further includes a stepped surface 226 definedtherein. In the embodiment shown, the stepped surface 226 is formed inthe outer edge 224, such that the stepped surface 226 is substantiallyparallel to the bottom surface 220. The stepped surface 226 defines arecess for receiving the second edge ring component 216. Generally, theheight of the first edge ring component 214 is limited by the height ofthe electrostatic chuck 202. For example, the inner edge 222 of thefirst edge ring component 214 does not extend above the height of theelectrostatic chuck 202. As such, the first edge ring component 214protects a side of the electrostatic chuck 202. In some embodiments, thesubstrate 101, when positioned on the electrostatic chuck 202, extendspartially over the first edge ring component 214.

The second edge ring component 216 includes a top surface 228, a bottomsurface 230, an inner edge 232, and an outer edge 234. The top surface228 is substantially parallel to the bottom surface 230. The inner edge232 is substantially parallel to the outer edge 234 and substantiallyperpendicular to the bottom surface 230. In one embodiment, the secondedge ring component 216 is interfaced with the first edge ring component214 via the bottom surface 230. For example, the bottom surface 230 ofthe second edge ring component 216 interfaces with the stepped surface226 in the first edge ring component 214. In another embodiment, thesecond edge ring component 216 may further include a stepped surface 236defined therein. In the embodiment shown, the stepped surface 236 isformed in the inner edge 232, such that the stepped surface 236interfaces with the stepped surface 226 of the first edge ring component214. When interfaced with the first edge ring component 214, the inneredge 232 of the second edge ring component 216 is spaced from thesubstrate 101. For example, the inner edge 232 of the second edge ringcomponent 216 may be spaced between about 0.02 mm and about 0.1 mm fromthe substrate 101.

In one embodiment, when interfaced, the first edge ring component 214and the second edge ring component 216 forms a continuous bottom surface238 and a continuous top surface 240. In another embodiment, wheninterfaced, the first edge ring component 214 and the second edge ringcomponent 216 do not form a continuous bottom surface 238 or acontinuous top surface 240. Rather, in some embodiments, the top surface218 of the first edge ring component 214 may be higher than the topsurface 228 of the second edge ring component 216. In other embodiments,the bottom surface 230 of the second edge ring component 216 may sitbelow the bottom surface 220 of the first edge ring component 214. Thus,in some embodiments, the first edge ring component 214 and the secondedge ring component 216 do not form a continuous top or bottom surface.

The process kit further includes an adjustable tuning ring 150 having atop surface 254 and a bottom surface 256. The adjustable tuning ring 150may be formed from a conductive material, such as aluminum. Theadjustable tuning ring 150 is disposed beneath the edge ring 210. Forexample, the adjustable tuning ring 150 is disposed beneath the secondedge ring component 216. The adjustable tuning ring 150 contacts thebottom surface of the 238 of the edge ring 210. For example, theadjustable tuning ring 150 contacts the bottom surface 230 of the secondedge ring component 216. In one embodiment, the adjustable tuning ring150 extends down the length of the electrostatic chuck 202 and thecooling plate 204, such that the adjustable tuning ring 150 has a heightsubstantially equal to the combined height of the electrostatic chuck202 and the cooling plate 204. As such, the adjustable tuning ring 150is able to couple power from the cooling plate 204 to the edge ring 210.

The adjustable tuning ring 150 may circumscribe the cooling plate 204,thus forming a laterally spaced gap 258. In one example, the laterallyspaced gap 258 is greater than 0 inches and less than or equal to 0.03inches. The adjustable tuning ring 150 interfaces with a lift pin 260.For example, the lift pin 260 may be operably coupled with theadjustable tuning ring 150. The lift pin 260 is driven by the liftmechanism 182. In some embodiments, the lift pin 260 may be driven by alift mechanism (not shown) independent from the lift mechanism 182. Thelift mechanism 182 allows the adjustable tuning ring 150 to be movedvertically within the chamber 100. As a result of the vertical movementof the tuning ring 150, the lift mechanism 182 raises the second edgering component 216. The second edge ring component 216 may be raisedabove the first edge ring component 214, thus forming a gap (299 in FIG.4B) between the stepped surface of the first edge ring component and thestepped surface of the second edge ring component.

In one embodiment, the adjustable tuning ring 150 may include a coating263 formed on the top surface 254 of the adjustable tuning ring 150. Forexample, the coating 263 may be a yttria oxide coating or a gel-likecoating. The coating 263 is used to limit the chemical reaction betweenthe plasma and the adjustable tuning ring 150 and thus limits particlecreation and ring damage. In another embodiment, one or more dielectricpads (e.g., Teflon pads) 306 are positioned in between the edge ring 210and the electrostatic chuck, on which the edge ring 210 sits.

In another embodiment, such as that shown in FIG. 2B, the adjustabletuning ring 150 may be moved manually, thus eliminating the need for thelift pin 260. The tuning ring 150 may include a cavity 262 and an accessorifice 264 formed therein. The access orifice 264 is formed from a topof the adjustable tuning ring 150, and extends down into the cavity 262.The access orifice 264 has a first diameter 266 that is smaller than asecond diameter 268 of the cavity 262. The cavity 262 is formed beneaththe access orifice 264. The cavity 262 is formed down to a bottom of thetuning ring 150. The cavity 262 is configured to house a screw 270. Thescrew 270 may be turned via a hex key (not shown), for example,extending into the cavity 262 via the access orifice 264 such that thescrew 270 can raise/lower the tuning ring 150.

Discussing FIGS. 2A and 2B in conjunction, the process kit 200 mayfurther include a quartz ring 272. The quartz ring 272 includes anannular shaped body 274 having a top surface 276, a bottom surface 278,an inner edge 280, and an outer edge 282. The top surface 276 issubstantially parallel to the bottom surface 278. The inner edge 280 issubstantially parallel to the outer edge 282, and substantiallyperpendicular to the bottom surface 278. The inner edge 280 ispositioned adjacent the adjustable tuning ring 150 and the edge ring210.

FIG. 3 is a simplified cross sectional view of a portion of theprocessing chamber of FIG. 1 depicting two capacitances, according toone embodiment. Power may be coupled from the cathode 204 to the edgering 210 along two paths through two capacitances 302, 304. The amountof power coupled depends on the capacitance along these two pathsrelative to the capacitance 305 between the ring 210 and the plasma.Depending on the plasma conditions, the capacitance 305 may vary. Forexample, the capacitance 305 may vary from 5 pF up to 150 pF. In anotherexample, the capacitance 304 may vary between about 10 pF and about 500pF due to the formation of a parallel plane capacitor between the twoedge ring components 214, 216 as the adjustable tuning ring 150 is movedup and down. The capacitance 302 may also vary when the adjustabletuning ring 150 moves up and down because there is an area of overlapbetween the adjustable tuning ring 150 and the cathode 204. Thepositioning of the adjustable tuning ring 150 and the cathode 204 formsa parallel plate capacitor. As the adjustable tuning ring 150 moves upand down, the area of overlap between the adjustable tuning ring 150 andthe cathode 204 varies, which results in a varying capacitance 302.Nevertheless the capacitance 302 variation is limited because theamplitude of the vertical movement is small relatively to the length ofthe adjustable tuning ring 150 overlapping with the cathode 204 Forexample, the amplitude of the vertical movement may be about 0 mm toabout 2 mm, while the length of the adjustable tuning ring 150 thatoverlaps the cathode is about 3 cm. As a result, the capacitance 302remains above some threshold amount. For example, the capacitance 302may remain above 1000 pF. Therefore, the capacitance between the cathode204 and the edge ring 210, which is the sum of the capacitances 302 and304, is always at least on order of magnitude higher than thecapacitance 305. As such, the potential, V_(DC), of the edge ring 210remains nearly constant. For example, the potential variation may notexceed 5%. Maintaining the voltage, V_(DC), applied to the edge ring 210as constant allows for control of a plasma sheath about the substrate101 and the edge ring 210. The effect of which, is discussed in moredetail below in conjunction with FIGS. 4A and 4B.

FIG. 4A illustrates a portion of the processing chamber 100, accordingto one embodiment, illustrating another advantage of the presentdisclosure. The voltage, V_(DC), can be used to control plasma sheath404 profile at an edge 406 of the substrate 101 to compensate forcritical dimension uniformity at the substrate edge 406. The plasmasheath 404 is a thin region of strong electric fields formed by spacecharge that joins the body of the plasma to its material boundary.Mathematically, the sheath thickness, d, is represented by theChild-Langmuir equation:

$d = {\frac{2}{3}\left( \frac{ɛ}{i} \right)^{\frac{1}{2}}\left( \frac{2e}{m} \right)^{\frac{1}{4}}\left( {V_{p} - V_{D\; C}} \right)^{\frac{3}{4}}}$

Where i is the ion current density, ε is the permittivity of vacuum, eis the elementary electric charge, V_(p) is the plasma potential, andV_(DC) is the DC voltage.

In the case of an etch reactor, a plasma sheath 404 is formed betweenthe plasma and the substrate 101 being etched, the chamber body 102, andevery other part of the processing chamber 100 in contact with theplasma. The ions produced in a plasma are accelerated in the plasmasheath and move perpendicular to the plasma sheath. Controlling theV_(DC), i.e., controlling the voltage applied to the edge ring 210,affects the thickness, d, of the sheath 404. The sheath thickness, d, ofsheath 404 may be measured with respect to the edge ring 210. Forexample, the thickness, d, is depicted in FIGS. 4A and 4B. In theembodiment shown, actuating the adjustable tuning ring 150 raises secondedge ring component 216. Because V_(DC) remains constant, the sheaththickness above the edge ring 210 remains constant. Therefore actuatingthe adjustable tuning ring 150 vertically raises the sheath 404 withoutimpacting the sheath thickness. Thus, moving the adjustable tuning ring150 affects the shape of the sheath 404 at the substrate 101 edge 406,which in turn controls the direction of plasma ions.

FIG. 4B illustrates the portion of the processing chamber 100 of FIG.4A, with the second edge ring component 216 in the raised position. Asillustrated, and as discussed in FIG. 4A, raising the adjustable tuningring 150 raises the second edge ring component 216, which in turn raisesthe sheath 404. Because the potential, V_(DC), remains nearly constantas a result of a nearly fixed capacitance 302, the sheath 404 thickness,d, remains constant throughout.

Referring back to FIG. 1, control of the adjustable tuning ring may becontrolled by a controller 191. The controller 191 includes programmablecentral processing unit (CPU) 192 that is operable with a memory 194 anda mass storage device, an input control unit, and a display unit (notshown), such as power supplies, clocks, cache, input/output (I/O)circuits, and the liner, coupled to the various components of theprocessing system to facilitate control of the substrate processing.

To facilitate control of the chamber 100 described above, the CPU 192may be one of any form of general purpose computer processor that can beused in an industrial setting, such as a programmable logic controller(PLC), for controlling various chambers and sub-processors. The memory194 is coupled to the CPU 192 and the memory 194 is non-transitory andmay be one or more of readily available memory such as random accessmemory (RAM), read only memory (ROM), floppy disk drive, hard disk, orany other form of digital storage, local or remote. Support circuits 196are coupled to the CPU 192 for supporting the processor in aconventional manner. Charged species generation, heating, and otherprocesses are generally stored in the memory 194, typically as softwareroutine. The software routine may also be stored and/or executed by asecond CPU (not shown) that is remotely located from the processingchamber 100 being controlled by the CPU 192.

The memory 194 is in the form of computer-readable storage media thatcontains instructions, that when executed by the CPU 192, facilitatesthe operation of the chamber 100. The instructions in the memory 194 arein the form of a program product such as a program that implements themethod of the present disclosure. The program code may conform to anyone of a number of different programming languages. In one example, thedisclosure may be implemented as a program product stored on acomputer-readable storage media for use with a computer system. Theprogram(s) of the program product define functions of the embodiments(including the methods described herein). Illustrative computer-readablestorage media include, but are not limited to: (i) non-writable storagemedia (e.g., read-only memory devices within a computer such as CD-ROMdisks readable by a CD-ROM drive, flash memory, ROM chips, or any typeof solid-state non-volatile semiconductor memory) on which informationis permanently stored; and (ii) writable storage media (e.g., floppydisks within a diskette drive or hard-disk drive or any type ofsolid-state random-access semiconductor memory) on which alterableinformation is stored. Such computer-readable storage media, whencarrying computer-readable instructions that direct the functions of themethods described herein, are embodiments of the present disclosure.

While the foregoing is directed to specific embodiments, other andfurther embodiments may be devised without departing from the basicscope thereof, and the scope thereof is determined by the claims thatfollow.

What is claimed is:
 1. A process kit for a substrate processing chamber, the process kit comprising: a ring having a first ring component and a second ring component, the first ring component interfaced with the second ring component such that the second ring component is movable relative to the first ring component to form a gap therebetween; an adjustable tuning ring positioned beneath the second ring component and contacting a bottom surface of the second ring component, the adjustable tuning ring having a top surface and a bottom surface, the top surface of the adjustable tuning ring contacting the second ring component; and an actuating mechanism interfaced with the bottom surface of the adjustable tuning ring, the actuating mechanism configured to actuate the adjustable tuning ring such that the gap between the first ring component and the second ring component is varied.
 2. The process kit of claim 1, wherein the adjustable tuning ring is formed from a conductive material.
 3. The process kit of claim 1, wherein the first ring component comprises: a stepped surface formed therein.
 4. The process kit of claim 3, wherein the second ring component comprises: a stepped surface formed therein, wherein the stepped surface of the second ring component interfaces with the stepped surface of the first ring component.
 5. The process kit of claim 1, wherein the actuating mechanism comprises: a lift pin having a first end and a second end, the first end of the lift pin contacting the bottom surface of the adjustable tuning ring, the second end of the lift pin in communication with a lift mechanism.
 6. The process kit of claim 1, wherein the actuating mechanism is configured to move up and down a plasma sheath formed between a plasma and the ring while maintaining a plasma sheath thickness nearly constant by raising and lowering the second ring component.
 7. The process kit of claim 6, wherein the adjustable tuning ring comprises: an annular body having the top surface and the bottom surface of the adjustable tuning ring; a cavity formed in the bottom surface of the annular body; and an access orifice formed in the annular body, the access orifice extending from the top surface of the annular body into the cavity.
 8. The process kit of claim 7, wherein the cavity has a first diameter and the access orifice has a second diameter, the first diameter being larger than the second diameter, and the actuating mechanism is a screw disposed at least partially in the cavity, the screw configured to be rotated through the access orifice to actuate the adjustable tuning ring.
 9. A process kit for a substrate processing chamber, the process kit comprising: a ring having a first ring component and a second ring component, the first ring component interfaced with the second ring component such that the second ring component is movable relative to the first ring component to form a gap therebetween; an adjustable tuning ring positioned beneath the second ring component and radially outside of the first ring component, the adjustable tuning ring having a top surface and a bottom surface, the top surface of the adjustable tuning ring contacting a bottom surface of the second ring component; and an actuating mechanism interfaced with the bottom surface of the adjustable tuning ring, the actuating mechanism configured to actuate the adjustable tuning ring such that the gap between the first ring component and the second ring component is varied.
 10. The process kit of claim 9, wherein the adjustable tuning ring is formed from a conductive material.
 11. The process kit of claim 9, wherein the first ring component comprises: a stepped surface formed therein.
 12. The process kit of claim 11, wherein the second ring component comprises: a stepped surface formed therein, wherein the stepped surface of the second ring component interfaces with the stepped surface of the first ring component.
 13. The process kit of claim 9, wherein the actuating mechanism comprises: a lift pin having a first end and a second end, the first end of the lift pin contacting the bottom surface of the adjustable tuning ring, the second end of the lift pin in communication with a lift mechanism.
 14. The process kit of claim 9, wherein the actuating mechanism is configured to move up and down a plasma sheath formed between a plasma and the ring while maintaining a plasma sheath thickness nearly constant by raising and lowering the second ring component.
 15. The process kit of claim 9, wherein the adjustable tuning ring comprises: an annular body having the top surface and the bottom surface of the adjustable tuning ring; a cavity formed in the bottom surface of the annular body; and an access orifice formed in the annular body, the access orifice extending from the top surface of the annular body into the cavity.
 16. The process kit of claim 15, wherein the cavity has a first diameter and the access orifice has a second diameter, the first diameter being larger than the second diameter, and the actuating mechanism is a screw disposed at least partially in the cavity, the screw configured to be rotated through the access orifice to actuate the adjustable tuning ring.
 17. A method of processing a substrate, comprising: positioning the substrate on a substrate support disposed in a substrate processing chamber; forming a plasma above the substrate; and adjusting a height of a ring component of an edge ring by actuating an adjustable tuning ring interfaced with the ring component to change a direction of one or more ions at an edge of the substrate.
 18. The method of claim 17, wherein the adjusting the height of the ring component moves a plasma sheath formed between the plasma and the edge ring while maintaining a plasma sheath thickness nearly constant.
 19. The method of claim 17, wherein the actuating the adjustable tuning ring comprises raising or lowering one or more lift pins in contact with a bottom surface of the adjustable tuning ring.
 20. The method of claim 17, wherein the adjustable tuning ring comprises a cavity formed in a bottom surface of the adjustable tuning ring and an access orifice formed in the adjustable tuning ring, the access orifice extending from a top surface of the adjustable tuning ring into the cavity, and the actuating the adjustable tuning ring comprises rotating a screw disposed at least partially in the cavity. 